We have seen a few instances of similar behavior to what you are describing, and the above steps fixed the problem. In the cases we have seen, the database prefix (the part before the underscore, _) has not been displayed in cPanel, and a new database cannot be created. After running the commands above, the prefix is again displayed, databases are listed, and new databases can again be created.

If the above steps do not help, please submit a ticket so that we may log into the server, investigate directly and fix the problem for you.